This material is actually a transparent glass-ceramic manufactured by
Schott Glaswerkes.

ROBAX® glass-ceramic has a thermal
endurance far exceeding that of normal tempered glass. Tempered glass is
generally limited to applications that do not exceed 500F. However, ROBAX®
is designed to operate at temperatures ranging from minus 400F. to plus
1400F.

Glass-ceramic was invented in the 1960s. Its thermal endurance and
stability make it ideal for many products: from stove tops and cookware, to
missile nose cones and astronomical telescope mirror substrates. Transparent
glass-ceramic, introduced in 1970s, is much more difficult and expensive to
make than ordinary glass. As a result, it also has a different appearance
including color, surface texture, and some small bubbles or inclusions that
are natural to its composition and have no effect on its strength or
performance.

We've placed a cutting torch below
the ROBAX® and heated it until red-hot.Then cold water was
poured on the glass from above - with NO breakage.

Because of its special composition and processing this
unique material can withstand a quench into ice water from red hot temperatures.
With ROBAX® Glass-Ceramic windows in your stove or fireplace, you can
enjoy the fire view with the assurance the window has been designed with a
superior margin of safety for your home and your family.

PHYSICAL PROPERTIES OF 1400 DEGREE ROBAX® TRANSPARENT
GLASS-CERAMIC

Normal Service

Extreme Service

Thermal Shock

Coefficient of Thermal Expansion

1400 F.

1475 F.

1400 F.

+1.6X10-7in./in./ F.

NOW .... One glass can supply all of your high temperature requirements.
Unlike tempered glass, 1400 Glass-Ceramic is unstressed. It can easily be cut
and finished using standard glass cutting tools.

Easily cut and sanded - even drilled. Will not shatter (like tempered
glass).

Good strength. Fire to Ice without breaking.

This is an excellent replacement in most applications for any of the
following glasses - PYREX®, BOROFLOAT® , TEMPAX® , VYCOR® , PYROCERAM® , and
NEOCERAM® . Typical applications include--